This invention relates in general to the field of communications and in particular to a system and method for communicating information at a customer premises using inverse multiplex ATM (IMA) functionality.
Historically, voice, video, data, and other services have been provided separately, using multiple facilities and separate wiring. As a result, communities requiring such services have usually faced relatively large initial expenses for implementing a system, subsequently increasing system capacity, and maintaining the system on an ongoing basis. Attempts to integrate such services to offset these inadequacies have typically forced users in these communities to accept a number of undesirable limitations, for example, limitations as to the generality of data services available.
Communications needs continue to expand on a global scale. With the growing demand for communications, and despite the limitations associated with prior systems, there is a concurrent expansion in the demand for audio, video, data, and other services provided to user communities. This is particularly true considering the recent rise in importance of packet-based audio, video, data, and other communications that rely on Asynchronous Transfer Mode (ATM), Internet Protocol (IP), Frame Relay (FR), and other packet-based protocols. For example, users in a community such as an apartment complex or other shared tenant environment may have telephones, personal computers, facsimile machines, and other devices allowing them to interface to the public switched telephone network (PSTN), the Internet, and other suitable networks. Previous systems do not provide voice, video, data, and other services in an integrated manner using a system having relatively low implementation, scaling, and ongoing maintenance costs. As a result of these and other inadequacies, previous systems are often inadequate to address the current and future needs of many user communities.
According to the present invention, disadvantages and problems associated with previous systems and methods for communicating information are substantially reduced or eliminated.
According to one embodiment, a system for communicating information at a customer premises includes a connecting link to communicate ATM cells. A first switching system coupled to a central office using a first link receives from the central office, using the first link, ATM cells for at least first and second virtual circuits. The first switching system communicates ATM cells for the second virtual circuit using the connecting link. A second switching system coupled to the central office using a second link receives from the central office, using the second link, ATM cells for at least the first and second virtual circuits. The second switching system communicates ATM cells for the first virtual circuit using the connecting link. The first switching system receives the ATM cells for the first virtual circuit from the second switching system, using the connecting link, and sequences all ATM cells for the first virtual circuit using first Inverse Multiplex ATM (IMA) functionality. The second switching system receives the ATM cells for the second virtual circuit from the first switching system, using the connecting link, and sequences all ATM cells for the second virtual circuit using second IMA functionality.
According to another embodiment, a system for communicating information at a distributed central includes a connecting link to communicate ATM cells. A first central office switching system receives ATM cells from a first link for at least first and second virtual circuits and communicates ATM cells for the second virtual circuit using the connecting link. A second central office switching system receives ATM cells from a second link for at least the first and second virtual circuits and communicates ATM cells for the first virtual circuit using the connecting link. The first switching system receives the ATM cells for the first virtual circuit from the second switching system, using the connecting link, and sequences all ATM cells for the first virtual circuit using first IMA functionality. The second switching system receives the ATM cells for the second virtual circuit from the first switching system, using the connecting link, and sequences all ATM cells for the second virtual circuit using second IMA functionality.
The present invention provides a number of important technical advantages over previous systems and methods. According to the present invention, all cells belonging to a particular virtual circuit are routed to the same destination device, in a distributed system containing multiple physical devices, and then properly sequenced using IMA functionality associated with the destination device. Cell sequencing therefore occurs independent of cells belonging to other virtual circuits and routed to other destination devices. Routing of cells among the distributed devices occurs over connecting links appropriate for the configuration of the devices. Unlike previous systems, the present invention allows the IMA protocol to be used in a distributed system in which multiple communication links carry ATM traffic to and from the system and then terminate at different devices in the system. The present invention also reduces single points of failure within such a distributed system, at a customer premises or central office for example, since the failure of one device may eliminate its IMA processing for virtual circuits terminating at the failed device but may not affect IMA processing for virtual circuits terminating at other devices. While capacity may be reduced, the system may continue to process ATM traffic according to the number of non-failed devices present in the system.
Systems and method incorporating one or more of these or other technical advantages are well suited for modern user communities needing integrated voice and data services. Other technical advantages are readily apparent to those skilled in the art from the following figures, descriptions, and claims.